Large Numbers  Long Notes

Versions of Ackermann's Function

Much of the following information, including the names like ack-h,
originate with John Cowles, "Ackermann's Original Function" and "more
on Ackermann", which were email messages sent to Robert S. Boyer, and
included as comments in an Nqthm file by Boyer in 1992.[2]

Kaitlyn Burnell, 2009: This version was created mainly with the goal
of creating fastest growth with the least total number of operators,
recursive calls, and conditional tests (each of which counts for "one
point"). It most closely resembles ack-mrr but is simpler in that
ack-kb(n,0)=n+2 for all n: